Field of the Invention
This invention relates to a CO sensor having an electromotive force response that operates at room temperature.
Description of the Related Arts
Shimizu, Hyodo, and Takeda proposed a CO sensor in which a Pt—Bi2O3 sensing electrode and a Pt reference electrode are provided on the same surface of a solid electrolyte substrate made of NASICON (WO2015/2060A). This CO sensor outputs electromotive forces between the sensing electrode and the reference electrode, and has a significant response to CO at room temperature. Furthermore, in this CO sensor, the sensing electrode and the reference electrode can be provided on the same surface of the solid electrolyte substrate, and it is not necessary to shield the reference electrode from an atmosphere to be analyzed. Moreover, this CO sensor can operate in a dry atmosphere, and a water reservoir for supplying water vapor to the sensing electrode is not required. Accordingly, this CO sensor has a simple structure.